The present disclosure relates to image processing devices used in imaging devices such as digital still and video cameras, and more particularly to techniques of image transformation including scaling-up, scaling-down, and rotation of images.
Some conventional image processing devices correct optical distortion in lenses, that is, so-called lens distortion (also referred to simply as “distortion”) in an electrical manner (see, e.g., Japanese Patent Publication No. 2004-080545 (Patent Document 1)). FIG. 8 illustrates a conventional image processing device described in Patent Document 1.
In FIG. 8, a horizontal correction unit 902 corrects horizontal distortion of an original image 900; a horizontally-corrected image memory unit 903 stores a horizontally corrected image obtained by this correction operation; and then a vertical correction unit 904 selectively obtains a horizontally-corrected image from the horizontally-corrected image memory unit 903, and corrects vertical distortion thereof. The horizontal correction parameter provided to the horizontal correction unit 902 and the vertical correction parameter provided to the vertical correction unit 904 are generated in a decoder 901 by decoding a correction vector provided from the outside world. For example, when lens distortion is corrected, the correction vector is changed depending on a change in the lens position in order to perform real-time correction.